dring: remove dead/deprecated API (TLS validation)

daemon/bin/dbus/configurationmanager-introspec.xml

daemon/bin/dbus/dbusconfigurationmanager.cpp

daemon/bin/dbus/dbusconfigurationmanager.h

daemon/src/client/configurationmanager.cpp

daemon/src/client/configurationmanager.h

daemon/src/dring/dring.h

daemon/src/ring_api.cpp

daemon/src/sip/Makefile.am

daemon/src/sip/tlsvalidation.c

daemon/src/sip/tlsvalidation.h

daemon/src/sip/tlsvalidator.cpp

daemon/src/sip/tlsvalidator.h

daemon/test/tlstest.cpp

gnome/src/dbus/configurationmanager-introspec.xml

gnome/src/dbus/dbus.c